1. Field of the Invention
The present invention relates to a disc device whose structure can be made thin, in which a disc having a center aperture is loaded, and the center aperture of the disc is held by a rotatable table.
2. Description of the Related Art
FIG. 13 is an enlarged sectional view of a disc-clamping means of a conventional disc device.
A rotatable table 1 is secured to a rotatable shaft 2a of a spindle motor 2, and is rotationally driven by the spindle motor 2. In the rotatable table 1, a disc-receiving portion 1a and a protrusion 1b are integrally formed. A clamping member 3, which opposes the rotatable table 1, is rotatably supported by a clamping arm 4.
While the clamping member 3 and the rotatable table 1 are separated from each other as a result of the upward rotation of the clamping arm 4, a disc D transported by a transporting roller 5 is supplied between the rotatable table 1 and the clamping member 3. When the disc D is positioned at a location where a center aperture D1 of the disc D matches the location of the protrusion 1b, the clamping arm 4 moves downward, so that the surrounding portion of the center aperture D1 of the disc D is clamped by the disc-receiving section 1 a of the rotatable table 1 and the clamping member 3.
As shown in FIG. 13, while the disc D is clamped to the rotatable table 1, the disc D is rotationally driven by the spindle motor 2 in order to reproduce or record data by a head opposing the disc D.
In the conventional disc clamping means shown in FIG. 13, the clamping member 3, disposed above the rotatable table 1, opposes the rotatable table 1, so that, as a mechanism for clamping a disc, a height equal to or greater than the sum of the thickness of the spindle motor 2, the thickness of the rotatable table 1, and the thickness of the clamping member 3 is required. Therefore, the overall height becomes large, so that there is a limit as to how thin the clamping means can be made.
One type of disc-clamping means is what is called a self-chucking type, in which a disc-holding means that elastically applies pressure to the peripheral edge portion defining the center aperture D1 of the disc D is provided at the protrusion 1b of the rotatable table 1. When the rotatable table of the self-chucking type is used, the clamping member 3 is not required, thereby making it possible to make the disc-clamping means thinner.
However, in the rotatable table of the self-chucking type, it is necessary to use a pushing means for pushing the peripheral portion defining the center aperture of the disc against the disc-receiving section of the rotatable table in order to elastically fit the disc-holding means to the center aperture of the disc. Therefore, the structure of the disc-clamping means becomes complicated.
Accordingly, in order to overcome the above-described problems, it is an object of the present invention to provide a disc device which makes it possible to clamp a disc by using a self-chucking-type rotatable table and a simple structure, and whose overall structure can be made thin.
In accordance with the present invention, there is provided a disc device with a simplified structure that can be made thin.
According to one aspect of the present invention, the disc device includes a rotatable table including a disc-receiving portion for receiving a surface of a disc, a protrusion for insertion into a center aperture of the disc, and a disc-holding member for elastically applying pressure to an inner peripheral edge surrounding the center aperture of the disc. A pressing member is provided that opposes the disc-receiving portion of the rotatable table. A pressing driver drives at least one of the rotatable table and the pressing member in a direction in which the rotatable table and the pressing member move towards each other in a manner that causes the disc-holding member to engage the inner peripheral edge of the disc.
According to another aspect of the invention, a disc device is provided that includes a rotatable table including a disc-receiving portion for receiving a surface of a disc, a protrusion for insertion into a center aperture of the disc, and a disc-holding member for elastically applying pressure to an inner peripheral edge surrounding the center aperture of the disc. A plate member is provided that opposes the disc-receiving portion of the rotatable table. A driving chassis, which supports the rotatable table, is movable relative to the plate member. A pressing driver drives the rotatable table toward the plate member in a manner that causes the disc-holding member to engage the inner peripheral edge of the disc. A disc passage space is formed between the plate member and the table when the plate member and the rotatable table are separated from each other. The plate member functions as a guide plate for the disc that passes into the passage space.
According to another aspect of the invention, a disc device is provided that includes a rotatable table including a disc-receiving portion for receiving a surface of a disc, a protrusion for insertion into a center aperture of the disc, and a disc-holding means for elastically applying pressure to an inner peripheral edge surrounding the center aperture of the disc. A pressing member opposing the disc-receiving portion of the rotatable table. A pressing member support shaft rotatably supports the pressing member. A pressing driver drives the pressing member toward the rotatable table in a manner that causes the disc-holding member to engage the inner peripheral edge of the disc.